A number of insurers have earned top marks in the sixth annual Corporate Equality Index published by the Human Rights Campaign Foundation (HRC). The Index rates employers on a scale from 0 to 100 percent on their treatment of gay, lesbian, bisexual and transgender (GLBT) employees, consumers and investors. Ratings are based on factors including nondiscrimination policies, diversity training and benefits for domestic partners and transgender employees. A few standouts: Allstate, Aon, Esurance, Hartford Financial Services and Massachusetts Mutual Life received the 100 percent rating for the first time. Chubb and Nationwide each received the 100 percent rating for the fourth year in a row. Overall, some 195 U.S. businesses employing more than 8.3 million workers earned the top rating of 100 percent in this year’s survey, a 41 percent increase on last year. Pause for thought: when the index was first released in 2002, only 13 companies employing 690,000 workers received the top rating.